Japan COVID-19 Task Force: a nation-wide consortium to elucidate host genetics of COVID-19 pandemic in Japan

To elucidate the host genetic loci affecting severity of SARS-CoV-2 infection, or Coronavirus disease 2019 (COVID-19), is an emerging issue in the face of the current devastating pandemic. Here, we report a genome-wide association study (GWAS) of COVID-19 in a Japanese population led by the Japan COVID-19 Task Force, as one of the initial discovery GWAS studies performed on a non-European population. Enrolling a total of 2,393 cases and 3,289 controls, we not only replicated previously reported COVID-19 risk variants (e.g., LZTFL1, FOXP4, ABO, and IFNAR2), but also found a variant on 5q35 (rs60200309-A at DOCK2) that was associated with severe COVID-19 in younger (<65 years of age) patients with a genome-wide significant p-value of 1.2 x 10-8 (odds ratio = 2.01, 95% confidence interval = 1.58-2.55). This risk allele was prevalent in East Asians, including Japanese (minor allele frequency [MAF] = 0.097), but rarely found in Europeans. Cross-population Mendelian randomization analysis made a causal inference of a number of complex human traits on COVID-19. In particular, obesity had a significant impact on severe COVID-19. The presence of the population-specific risk allele underscores the need of non-European studies of COVID-19 host genetics.

DsRNA induction of microRNA-155 disrupt tight junction barrier by modulating claudins.

BACKGROUND: The impaired barrier function of the airway epithelium due to RNA virus infection is closely related to the development and exacerbation of allergic airway inflammation. OBJECTIVE: In this study, we investigated the roles of microRNAs on the mechanisms of double-stranded RNA (dsRNA)-induced epithelial barrier dysfunction. METHODS: 16HBE14o- human bronchial epithelial cells were grown to confluence on Transwell inserts and exposed to poly-I:C. We studied epithelial barrier function by measuring transepithelial electrical resistance and paracellular flux of fluorescent markers and structure of tight junctions by immunofluorescence microscopy. RESULTS: Poly-I:C treated 16HBE14o- cells increased paracellular permeability. Knockdown of Toll-like receptor 3 and TRIF abrogated these effects. The expression of microRNA-155 (miR-155) was increased by poly-I:C in dose-dependent manner. Transfection of mir155 mimics into 16HBE14o- cells increased permeability and inhibited tight junction formation. Transfection of miR-155 inhibitor suppressed poly-I:C-induced barrier disruption. Poly-I:C treatment significantly decreased the expression of claudin members-claudin-1, -3, -4, -5, -9, -11, -16, -18 and -19. Transfection of miR-155 mimics showed similar changing expression pattern of claudin members with those of poly-I:C treatment. CONCLUSION: These results suggest that RNA virus infection can impair the epithelial barrier disruption mechanism by down-regulation of claudin members through the induction of miR-155.

Ramelteon for Delayed Sleep-wake Phase Disorder: A Case Report

Recently developed melatonin receptor agonists are expected to be effective for delayed sleep-wake phase disorder (DSWPD). To date, however, no study has described the effect of melatonin receptor agonists on DSWPD. We report the case of a 15-year-old girl with DSWPD who was successfully treated with ramelteon 4 mg at 7 PM. DSWPD symptoms were resolved; her sleep-wake and biological rhythms were normalized.

Relationship between Clozapine-Induced Electroencephalogram Abnormalities and Serum Concentration of Clozapine in Japanese Patients with Treatment-Resistant Schizophrenia

OBJECTIVE: The objective of this study was to investigate the relationship between the serum concentration of clozapine (C-CLZ), N-desmethylclozapine (N-CLZ) and the daily dose of CLZ (D-CLZ), and the relationships among CLZ and electroencephalogram (EEG) abnormalities. METHODS: Twenty-eight patients were recruited to this study, but 8 patients were excluded because clozapine was discontinued before the post-treatment measurement of EEG or C-CLZ. Ultimately, 20 patients (6 men, 14 women) with an average age of 36 years were enrolled. The subjects were divided into EEG normal and abnormal groups. C-CLZ and N-CLZ were measured at 4, 12, 26, and 52 weeks after initiating CLZ administration. RESULTS: All patients had normal baseline EEG signals, and 8 patients showed EEG abnormalities later. There were significant correlations between C-CLZ and D-CLZ, and between N-CLZ and D-CLZ. The C-CLZ/D-CLZ, N-CLZ/D-CLZ, and C-CLZ/N-CLZ ratio were not significantly different between the EEG normal and EEG abnormal groups. The EEG abnormal group had significant higher proportion of patients with high intra-individual variability in their C-CLZ/D-CLZ ratio. CONCLUSION: There is no relationship between C-CLZ and EEG abnormalities. However, patients with high intra-individual variability in their C-CLZ/D-CLZ ratio had greater possibility of exhibiting EEG abnormalities.

Successful Management of Clozapine-induced Akathisia with Gabapentin Enacarbil: A Case Report

The management of clozapine (CLZ)-induced adverse events affects patient prognoses. Akathisia is a relatively rare adverse event related to CLZ administration and thus the management of this syndrome is not well established. Here, we report a case of treatment-resistant schizophrenia wherein CLZ-induced akathisia was successfully managed with gabapentin enacarbil (GE). The patient was a 39-year-old woman who had been treated with atypical antipsychotics other than CLZ for three years with poor tolerability. Initiation of CLZ (400 mg/day) attenuated her psychotic symptoms, but was followed by moderate akathisia. Neither benzodiazepines nor biperiden improved the akathisia; however, akathisia was finally diminished with co-administration of GE. GE facilitated a dosage increase in CLZ (450 mg/day) for the improved management of pyschotic symptoms, and thus indirectly contributed to treatment of the patient’s schizophrenia. We suggest that GE is a useful candidate for the management of CLZ-induced akathisia. The improved management of treatment-induced akathisia and other adverse events can extend the potential application of CLZ for treatment-resistant schizophrenia.